It says that the Democrats lost two seats and the GOP gained two seats. But the current (pre-election) Senate composition was 51 Republicans and 49 Democrats. How can the Republicans gain 2 seats and still be at 51? And if the Democrats lost 2 seats why are they at 46 in that page, instead of 47?

Is it some weird accounting due to the fact that not every race has been called?

It's possible the number hasn't changed because the newly-elected Senators don't become actual Senators until January and they display current totals rather than election totals, but you're right; that's a very confusing page.
– Michael W.Nov 9 at 0:49

2 Answers
2

Not all the races are in yet. So they are starting by subtracting the races that are not called:

Arizona.

Florida.

Special election in Mississippi.

Two of those seats are Republican seats (Arizona and Mississippi). One is currently held by a Democrat (Bill Nelson in Florida). So that turns the 51-49 breakdown into a 49-48 breakdown. The Republicans (without those seats) have won 51 seats. That's two more than 49. The Democrats (without those seats) have won 46 seats. That's two less than 48.

This can of course still change. If the Republicans win all three seats (they were leading in all three the last time that I checked; Mississippi goes to a runoff if no one gets a majority), then they would have picked up three seats (they can't pick up Arizona and Mississippi as they already have them). If the Democrats win all three (despite being behind and Mississippi being very Republican), then they would have come up even.

You are correct though. In current returns, Republicans are only guaranteed not to lose any seats. Democrats are guaranteed to not lose more than three. But Republicans have made two Democrat to Republican pickups (net) while Democrats have lost two seats that they previously had. Actually Republicans picked up three and lost one for a net of two.

The election was less than two days ago. Not all the votes have been counted yet. As a result, some of the close races are yet to be "called".

The numbers at the top of the page you link to show that 51 seats have either been called in favor of republican candidates or are held by republicans and not up for election and, likewise, democrats have 46 seats. That leaves 3 seats that have not been called -- those are Florida, Arizona, and the Mississippi special election.

Note that "calling" a race is not official. It means the journalists at the New York times have decided that the outcome is clear. Even if some votes have not been counted, most races have a candidate with a strong lead and it is very unlikely that they will not win. For close races, the journalists hold off on calling it. Currently republicans are ahead in the three uncalled races, so people are reporting that democrats will likely lose seats.